1. Field of the Invention
The present invention relates to a workflow support system for supporting group works and workflows in a distributed environment in which a plurality of information processing equipment are connected by a network.
2. Description of the Related Art
Generally, a workflow represents a flow of work. In a business corporation, for example, suppose that one of the members of the corporation is going to purchase an article. First, the person prepares a purchase slip and then brings the purchase slip to the superior. The superior checks the purchase slip, stamps the approval, and sends the purchase slip to the accounting department. Based on the purchase slip, the accounting department orders the article. As seen in the above-mentioned workflow, the purchase slip flows from the person to the superior, and from the superior to the accounting department, thus advancing the workflow.
Here, each of the work to make the purchase slip, the work to check the purchase slip and stamp the approval, and the work to order the article, etc. is a unit of work, and the unit of each work is called a task. Therefore, a workflow can be considered a sequence of task. A task can be further divided into sub-tasks. Tasks can be performed by persons as in the foregoing example, and can automatically be performed by computers as, for example, in a data base retrieval.
Owing to the recent spread of information processing equipment, distributed environments have been developed, in which information processing equipment such as terminal equipment are provided in each of work fields and these plural information processing equipment are connected by a network system. The users of the information processing equipment each are to perform the assigned work.
Generally, the control information of the tasks is stored, for example, as one record in a data base. Each task necessarily has a side to receive a request of the task and a side to request the task (or, a side to execute a task and a side to receive the report). If these two sides are separately located on different local networks or information processing equipments, the one record must be shared by the both sides.
A system to support a workflow that connects a plurality of information processing equipments and users in such a distributed environment has been developed. Since sharing the foregoing record has been difficult to be realized, an electronic mail, for example, is generally used. And, it is a common exercise that a request of a work is sent out by the electronic mail, and the report of the work is asked to be sent back. Namely, a workflow is defined by defining a distribution path of a document transmitted as an electronic mail. For example, in the foregoing purchase slip, a distribution path from the maker to the accounting department through the superior is defined. According to the definition, the system to support a workflow distributes a purchase slip as an electronic mail. Further, the system to support a workflow controls a distribution history and can display a distribution state by a graphical presentation to trace the progress state of the workflow. InterNotes (trademark) from Lotus Corp. is a system which converts an electronic document, such as an electronic mail distributed in a workflow, into a markup language and opens it to the Internet. Thereby, external networks can refer to the electronic document of the system.
In a system using an electronic mail, it is necessary to send an electronic mail in order to execute the subsequent task. However, if the address is not found or the address change due to a transfer or the like is not informed, the system cannot send the electronic mail; thus a workflow is forced to be stopped in some case. In order to solve such a problem, there is a work low support system disclosed, for example, in the Japanese Published Unexamined Patent Application No. Hei 8-101817. In this system, a workflow is described according to rules such as the predicate logic and the like, and tasks described in the rules are sequentially executed. A workflow is performed by using another rule on the execution process, or by applying the other rule to the task that could not have been executed.
However, in the conventional workflow support system, the control information on the distribution history of electronic mails and the progress state of workflows is controlled to be closed in a data base for controlling a workflow support system sitting in alocal network. It is very difficult to utilize the information from the other networks or the other systems. Accordingly, companies and business establishments that employ different electronic mails and different workflow support systems cannot successfully accomplish such a workflow as to be transferred between companies and business establishments. Further, in case a similar workflow support system is used, the conventional system requires to always maintain the consistency between both systems by duplicating a control information base having an identical content to the data base of local networks on the paths where tasks of the workflow are transferred.
Naturally, it is possible to substitute the transmission of information among workflows flowing out from a local network by a usual electronic mail. However, there is a problem that the transmission is interrupted as to the distribution history of an electronic mail after having been sent out and the control information on the progress state of a workflow.